The sad thing is about all this is that having made the decision
to use these buttons from the start, Google has locked itself in
a mess of a UI-model. All Android apps would have to be
redesigned should they want to change it around and fix this. In
short, they’re stuck with a UI that sucks and they can’t fix
it because they didn’t think it through thoroughly before the
first launch.

Looks like they’re trying to fix this starting with the Galaxy Nexus by eliminating the hardware buttons but drawing them on-screen in the OS. Presumably, a future API revision could allow for apps that don’t need these buttons. Anyway, agree with his criticism of these two buttons completely. The Back button taking me somewhere unexpected was perhaps my single-biggest complaint both times I tested an Android phone.

The other lesson: the importance of getting things right, from the outset. If you’re designing just an app, you can fix many design errors later; if you’re designing an app platform, though, it’s hard to fix system-wide design errors without breaking existing apps.